3 REVIEW REPRODUCTIVE A&P, FETAL CONCEPTION & DEVELOPMENTTHIS WILL NOT BE COVERED IN THIS LECTURE—BE PREPARED TO ANSWER REVIEW QUESTIONS IN CLASSTHE QUIZ IN CLASS 1 WILL FOCUS ON CHANGES IN PREGNANCY AND TERMINOLOGY

30 Figure 3–2a Sperm penetration of an ovumFigure 3–2a Sperm penetration of an ovum. The sequential steps of oocyte penetration by a sperm are depicted moving from top to bottom. Source: Scanning electron micrograph from Nilsson, L. (1990). A child is born. New York: Dell Publishing.

32 Figure 3–5 Formation of primary germ layersFigure 3–5 Formation of primary germ layers. A, Implantation of a 71⁄2-day blastocyst in which the cells of the embryonic disc are separated from the amnion by a fluid-filled space. The erosion of the endometrium by the syncytiotrophoblast is ongoing. B, Implantation is completed by day 9, and extraembryonic mesoderm is beginning to form a discrete layer beneath the cytotrophoblast. C, By day 16 the embryo shows all three germ layers, a yolk sac, and an allantois (an outpouching of the yolk sac that forms the structural basis of the body stalk, or umbilical cord). The cytotrophoblast and associated mesoderm have become the chorion, and chorionic villi are developing. Source: Adapted from Marieb, E. N. (1998).

33 Figure 3–4 During ovulation, the ovum leaves the ovary and enters the fallopian tube. Fertilization generally occurs in the outer third of the fallopian tube. Subsequent changes in the fertilized ovum from conception to implantation are depicted.

38 Figure 3–10 Vascular arrangement of the placentaFigure 3–10 Vascular arrangement of the placenta. Arrows indicate the direction of blood flow. Maternal blood flows through the uterine arteries to the intervillous spaces of the placenta and returns through the uterine veins to maternal circulation. Fetal blood flows through the umbilical arteries into the villous capillaries of the placenta and returns through the umbilical vein to the fetal circulation.

39 Figure 3–7 Early development of primary embryonic membranesFigure 3–7 Early development of primary embryonic membranes. At 41⁄2 weeks, the decidua capsularis (placental portion enclosing the embryo on the uterine surface) and decidua basalis (placental portion encompassing the elaborate chorionic villi and maternal endometrium) are well formed. The chorionic villi lie in blood-filled intervillous spaces within the endometrium. The amnion and yolk sac are well developed. Source: Adapted from Marieb, E. N. (1998).

40 Figure 3–10 Vascular arrangement of the placentaFigure 3–10 Vascular arrangement of the placenta. Arrows indicate the direction of blood flow. Maternal blood flows through the uterine arteries to the intervillous spaces of the placenta and returns through the uterine veins to maternal circulation. Fetal blood flows through the umbilical arteries into the villous capillaries of the placenta and returns through the umbilical vein to the fetal circulation.

41 Figure 3–7 Early development of primary embryonic membranesFigure 3–7 Early development of primary embryonic membranes. At 41⁄2 weeks, the decidua capsularis (placental portion enclosing the embryo on the uterine surface) and decidua basalis (placental portion encompassing the elaborate chorionic villi and maternal endometrium) are well formed. The chorionic villi lie in blood-filled intervillous spaces within the endometrium. The amnion and yolk sac are well developed. Source: Adapted from Marieb, E. N. (1998).

42 Figure 3–6 Endoderm differentiates to form the epithelial lining of the digestive and respiratory tracts and associated glands. Source: Adapted from Marieb, E. N. (1998).

43 Figure 3–12 The actual size of a human conceptus from fertilization to the early fetal stage. The embryonic stage begins in the third week after fertilization; the fetal stage begins in the ninth week. Source: Adapted from Marieb, E. N. (1998).

46 REVIEW QUESTIONSWHAT IS THE SIGNIFICANCE OF THE ENDOMETRIAL (MUCOSAL) LAYER OF THE UTERUS?THE UTERUS IS MADE UP OF WHAT TYPE OF MUSCLE?ESTROGEN IS SECRETED BY THE_______?PROGESTERONE IS SECRETED BY THE_______?WHAT IS THE FUNCTION OF FSH AND LH?DESCRIBE MEIOSIS.

47 REVIEW QUESTIONS WHERE DOES FERTILIZATION OCCUR?THE BLASTOCYST DEVELOPS INTO THE ______.THE TROPHOBLAST DEVELOPS INTO THE ____.THE PLACENTA DEVELOPS FROM THE ______.WHICH SYSTEMS/STRUCTURES DEVELOP FROM THE MESODERM LAYER?

48 NAME THREE FACTORS THAT AFFECT FETAL DEVELOPMENT.WHAT IS THE ROLE OF THE BROAD AND ROUND LIGAMENTS?WHAT IS THE UPPER PORTION OF THE UTERUS CALLED?WHATS CHANGES OCCUR IN THE FUNCTION OF THE OVARIES AT ABOUT THE TH WEEK OF PREGNANCY?

53 REPRODUCTIVE SYSTEM OVARIESSTOP PRODUCING OVA. CORPUS LUTEUM IS ACTIVE WEEKS INTO PREGNANCY TO PRODUCE ESTROGEN AND PROGESTERONE. THEN WHAT HAPPENS?BREASTSINCREASED VASCULARITY AND SIZEHYPERTROPHY OF MAMMARY AVEOLIBECOME MORE NODULAR; NIPPLES ENLARGEPIGMENTATION OF AREOLA; COLUSTRUM

114 DISCOMFORTS OF PREGNANCYDETERMINE WHICH SYSTEM IS RESPONSIBLE FOR EACH OF THE DISCOMFORTS OF PREGNANCY.EXPLAIN HOW THE PHYSIOLOGICAL CHANGES THAT OCCUR IN EACH SYSTEM DURING PREGNANCY CAN BE RESPONSIBLE FOR THE DISCOMFORTS.WHAT INTERVENTIONS WOULD YOU USE TO TREAT THE DISCOMFORTS? (EBP)